Said geo



(No Model.)

Gf K. 8v H. C. FARRINGTON.

WITNESSES @Mli MEGHANIGAL TELEPHONE.

Patented Jan. 30,4 .1883.

lUNTTED STATES PATENT OEEICE.

GEORGE K. FARRINGTON AND BOMER O. FARBINGTON, OF KIRKSVILLE.

MlSSOURl, ASSIGNORS OF ONE-THIRD TO BRADFORD S.

POTTER, OF

EDINBOROUGH, PENNSYLVANIA, SAID GEO. K. FABRINGTON ASSIGNOR TO H. O. FARRINGTON.

.MECHANICAL TELEPHONE.

SPECIFICATION forming partof Letters Patent No. 271,324, dated January'SO, 1883.

Application tiled August 2S, 1882. (No model.)

To all whom it may concern Be it known that we, GEORGE K.FARRING ToN and HOMER C. FARRINGTON, citizens of the United States ofAmerica,residingatKirksville, in the county of Adair and State ot' Missouri, have invented certain new and useful Improvements in Mechanical Telephones', of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to improvements in that class of telephones termed mechanical, and is designed more especiallyas animprovement on the mechanical telephone invented by us, and for which United States Letters Patent No. 252,024 were granted to us on the 10th day of January, 1882.

The object of our prese-nt invention is to obviate the ringing or roaring sound and reverberation produced in telephones by the impact of sound upon the diaphragms, and thus secure a clear and distinct articulation of syllables and words, so necessary to have in a speaking-telephone.

A further object of our invention is to secure a firm and durable connection of the line-wire to the button of the diaphragm, and also se- Nrw...fw-ture a perfectly-equalized tension on each diaphragm in one instrument with each diaphragm in the other when the line between the two instruments is drawn, thus securing an equal or the claims.

The accompanying two gures of the drawings represent a vertical section and a front elevation ot1 the telephone, in which A is the case; B B', the diaphragms, attached to the diaphragm-frame C; and F, the rear wall of case,

forming a sounding-board. The combination end of which is inserted in achambered recess, n, in the sounding-board, F, the other end resting on a button, liz.

H is a metallic cap, to the inside of which is soldered or otherwise secured the ends of the line-Wire fz', (composed preferably of two strands of wire twisted togethen) which passes through the cylindrical tube j, upon the outside ot' which tube is a screw-thread to retain the nut l. A washer, m, is also secured to the tubej, and arranged under metal cap H. This metal cap my also rests upon a button, lr. The tube j and line i pass through the center of the diaphragms BB and buttons 7c 7c. Vhen the diaphragms are tacked or oth erwise secured on the frame O, the tube]- and line e' with button t' are passed through them, and also through la. The nut Z is then screwed onto the tnbej, and the diaphragms are drawn together, as shown in Fig. l, in the shape of an hour-glass. The tube G having been put into the recess n in sounding-board F, the diaphragms areinserted into the case A, the button la resting against the end of tube G. Now, when the line t'is tightened (by means ot' pulleys or otherwise) between the instruments, the two diaphragms in each instrument are brought to the same degree of tension, the diaphragm B being pressed inward by being drawn against tube G, and the diaphragm B being drawn inward also by the same tension of the line on the cap H and button L, thus equalizing the tension on both diaphragms. The tube G also forms a rigid center or sounding-post between the diaphragms B Band sounding-board F. This tube 0r sounding-post, being hollow, does not obstruct the sound-wave or vibration from one instrument to the other from first striking the diaphragms; but the sound, having first been impactedonthediaphragms,isinstantaneously transmitted by the tube to the sounding-board, lwhich resounds simultaneously with the diaphragms in the expansion and contraction ot' the air in the air-chambers D and E. The diaphragms being rendered rigid at the center by means of the buttons k k' and tube G, the vibrations of the surrounding parts of the diaphragme are concentrated to the center, shortcned, and quicliened, eftectually preventing the ringing and roaring so detrimental to clear articulation and ease in conversation. By this improvement a clear and sharp articulation is obtained, and conversation can be carried on Without making pauses between syllables and Words, (to allow ringing to subside,) as has hitherto been the case in telephones of this class. This tube or sounding-post is applicable to all telephones using` single or double diaphragms. It may be made ot' metal, Wood, or other suitable material.

It Will be observed that this organization and arrangement ot parts makes a very simple and cheap instrument.

We reserve the right to change the construction and shape of theinstrumentwithout departing from the spirit of the invention.

Havingthusdescribed ourinventiomwhatwe claim as new, and desire to secure by Letters Patent, is-

l. A mechanical telephone composed essen- GEORGE K. FARRINGTON. HOMEP. C. FARRINGTON.

Witnesses:

CEAS. B. OLDHAM, HENRY Bns'rMANN. 

